161641992 has 32 divisors (see below), whose sum is σ = 405730080. Its totient is φ = 53664000.

The previous prime is 161641981. The next prime is 161641993. The reversal of 161641992 is 299146161.

It is a super-2 number, since 2×161641992² = 52256267155456128, which contains 22 as substring.

It is a Smith number, since the sum of its digits (39) coincides with the sum of the digits of its prime factors.

It is a self number, because there is not a number n which added to its sum of digits gives 161641992.

It is not an unprimeable number, because it can be changed into a prime (161641993) by changing a digit.

It is a pernicious number, because its binary representation contains a prime number (11) of ones.

It is a polite number, since it can be written in 7 ways as a sum of consecutive naturals, for example, 7393 + ... + 19440.

It is an arithmetic number, because the mean of its divisors is an integer number (12679065).

Almost surely, 2^161641992 is an apocalyptic number.

161641992 is a gapful number since it is divisible by the number (12) formed by its first and last digit.

It is an amenable number.

161641992 is an abundant number, since it is smaller than the sum of its proper divisors (244088088).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

161641992 is a wasteful number, since it uses less digits than its factorization.

161641992 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 27093 (or 27089 counting only the distinct ones).

The product of its digits is 23328, while the sum is 39.

The square root of 161641992 is about 12713.8504002525. The cubic root of 161641992 is about 544.7343114816.

The spelling of 161641992 in words is "one hundred sixty-one million, six hundred forty-one thousand, nine hundred ninety-two".